The phase change memory has been received attention as a next-generation nonvolatile memory referred to as a universal memory. The phase change memory is an element performing memorizing whether a part of a phase change film is put into an amorphous state or into a crystalline state through the use of the “phase change film” and performing read-out through the use of resistance change accompanied with the state change.
As the phase change film, materials, such as a chalcogenide material, and a mixture of germanium (Ge), antimony (Sb) and tellurium (Te), generally referred to as GST, are used. There has been a problem of interlayer peeling between the chalcogenide material and an upper electrode provided on the material.
In order to solve this problem, in Patent Document 1, a method for forming an electrode for a memory material of a phase change memory device has been disclosed. The method includes the steps of: forming a first layer adhered on the top surface of the memory material and which contains an nitride (ANx) (where, A is either one of titanium (Ti) or tungsten (W), and x is smaller than 1.0); and forming a second layer adhered on the first layer and which contains an nitride (ANy) (where, y is equal to or greater than 1.0).    Patent Document 1: Japanese Patent Application Laid-Open Publication No. 2007-243180.